CN111097482A

CN111097482A - Phosphorus-containing high-silicon molecular sieve and preparation method and application thereof

Info

Publication number: CN111097482A
Application number: CN201811259943.0A
Authority: CN
Inventors: 毛以朝; 龙湘云; 张润强; 赵阳; 赵广乐
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2018-10-26
Filing date: 2018-10-26
Publication date: 2020-05-05
Anticipated expiration: 2038-10-26
Also published as: CN111097482B

Abstract

The invention relates to a phosphorus-containing high-silicon molecular sieve, a preparation method and application thereof, wherein the pore volume of the molecular sieve is 0.20-0.50 mL/g, and the specific surface area is 260-600 m²The content of silicon, aluminum and phosphorus of the molecular sieve is 90-99.8 wt%, 0.1-9.0 wt% and 0.01-2.5 wt%, respectively, calculated by oxide and based on the dry weight of the molecular sieve; in an XRD spectrogram of the molecular sieve, the diffraction angle position of a first intensity peak is 5.9-6.9 degrees, the diffraction angle position of a second intensity peak is 10.0-11.0 degrees, and the diffraction angle position of a third intensity peak is 15.6-16.7 degrees. Compared with the conventional amorphous silica-alumina material, the phosphorus-containing high-silica molecular sieve disclosed by the invention has better nitrogen stability, and shows higher hydrocracking activity when being used for preparing a hydrocracking catalyst.

Description

Phosphorus-containing high-silicon molecular sieve and preparation method and application thereof

Technical Field

The present disclosure relates to a phosphorus-containing high-silicon molecular sieve, a preparation method and an application thereof.

Background

Commercial hydrocracking feeds include heavy, inferior fractions such as VGO, containing significant amounts of polycyclic aromatic hydrocarbons and naphthenes, as well as significant amounts of nitrogen-containing compounds. Conventional hydrocracking feed nitrogen mass percentages are generally between 0.1 and 0.2. However, secondary processing of oil refining such as coking, solvent deasphalting, etc. often produces large amounts of nitrogen-containing compounds, often with nitrogen contents exceeding 0.3%, and some even reaching 0.6%, which makes it difficult to remove the nitrogen contents to 10-100ppm levels that can be tolerated by conventional molecular sieve type hydrocracking catalysts after the use of conventional refining catalysts. Amorphous silica-alumina or silica-containing alumina having weak acidity is generally used as an acidic component as a main acidic component of the high nitrogen content hydrocracking catalyst.

The prior art generally uses silicon oxide and aluminum oxide salt solutions to synthesize weakly acidic silicon and aluminum at low pH, and also uses alumina grafted on a silicon oxide precursor or alumina grafted on a silicon oxide precursor, and forms silicon and aluminum tetrahedrons through further reaction, thereby generating acidity in the sample.

ZL97121663.0 discloses a hydrocracking catalyst especially suitable for producing middle distillate, comprising an amorphous silica-alumina component and a small pore alumina binder, the amorphous silica-alumina component being present in an amount of 30-60 wt%, at least one group VIB element and at least one group VIII element, the total amount of hydrogenation metal oxides being 20-35 wt%, the remainder being the small pore alumina binder, characterized in that the specific surface of the catalyst is 150-²The pore volume is 0.25-0.50mg/g, the pore distribution of 4-15nm is 60-90%, and the infrared acidity is 0.30-0.50 mmol/g.

Although the methods can generate certain acidity, in the synthesis process, in order to keep the stability of the matrix structure, a large amount of non-framework hexa-coordinated aluminum exists in the obtained sample, so that the material is ordered in a short range, and the long-range order is difficult to achieve.

Disclosure of Invention

The present disclosure is directed to a phosphorus-containing high silicon molecular sieve having higher stability against nitrogen than conventional amorphous silica-alumina materials, and a method for preparing the same and use thereof.

To achieve the above object, a first aspect of the present disclosure: providing a phosphorus-containing high-silicon molecular sieve, wherein the pore volume of the molecular sieve is 0.20-0.50 mL/g, and the specific surface area is 260-600 m²The content of silicon, aluminum and phosphorus of the molecular sieve is 90-99.8 wt%, 0.1-9.0 wt% and 0.01-2.5 wt%, respectively, calculated by oxide and based on the dry weight of the molecular sieve;

in an XRD spectrogram of the molecular sieve, the diffraction angle position of a first intensity peak is 5.9-6.9 degrees, the diffraction angle position of a second intensity peak is 10.0-11.0 degrees, and the diffraction angle position of a third intensity peak is 15.6-16.7 degrees.

Optionally, in an XRD spectrogram of the molecular sieve, the diffraction angle position of a first intensity peak is 6.1-6.8 °, the diffraction angle position of a second intensity peak is 10.2-10.7 °, and the diffraction angle position of a third intensity peak is 15.8-16.5 °.

Optionally, in the XRD spectrum of the molecular sieve, I₁/I_{23.5～24.5°}Is 3.0 to 11.0, I₂/I_{23.5～24.5°}Is 2.9 to 7.0, I₃/I_{23.5～24.5°}1.0 to 4.0, wherein I₁Is the peak height of the first strong peak, I₂Is the peak height of the second strong peak, I₃Is the peak height of the third strong peak, I_{23.5～24.5°}The peak height of the diffraction angle peak with the diffraction angle position of 23.5-24.5 degrees.

Optionally, in an XRD spectrogram of the molecular sieve, the diffraction angle position of a fourth intensity peak is 20.4-21.6 degrees, and the diffraction angle position of a fifth intensity peak is 11.8-12.8 degrees.

Optionally, in an XRD spectrogram of the molecular sieve, the diffraction angle position of a fourth intensity peak is 20.8-21.4 degrees, and the diffraction angle position of a fifth intensity peak is 12.1-12.6 degrees; and/or the presence of a gas in the gas,

I₄/I_{23.5～24.5°}1.0 to 4.0, I₅/I_{23.5～24.5°}1.0 to 2.0, wherein I₄Is the peak height of the fourth strong peak, I₅Is the peak height of the fifth strong peak, I_{23.5～24.5°}The peak height of the diffraction angle peak with the diffraction angle position of 23.5-24.5 degrees.

In a second aspect of the present disclosure: there is provided a process for preparing a phosphorus-containing, high silicon molecular sieve according to the first aspect of the present disclosure, the process comprising the steps of:

a. carrying out hydro-thermal treatment on a phosphorus-containing molecular sieve raw material for 0.5-10 h at the temperature of 350-700 ℃ and the pressure of 0.1-2 MPa in the presence of water vapor to obtain a hydro-thermally treated molecular sieve material; calculated by oxide and based on the dry weight of the phosphorus-containing molecular sieve raw material, the phosphorus content of the phosphorus-containing molecular sieve raw material is 0.1-15 wt%, and the sodium content is 0.5-4.5 wt%;

b. b, adding water into the molecular sieve material subjected to the hydrothermal treatment obtained in the step a, pulping to obtain first slurry, heating the first slurry to 40-95 ℃, keeping the temperature, adding a first acid solution into the first slurry, wherein the adding amount of the first acid solution enables the pH value of the first slurry subjected to acid addition to be 2.5-4, carrying out constant temperature reaction for 0.5-20 h, and collecting a first solid product;

c. b, adding water into the first solid product obtained in the step b, pulping to obtain second slurry, heating the second slurry to 40-95 ℃, keeping the temperature, continuously adding a second acid solution into the second slurry, wherein the adding amount of the second acid solution enables the pH value of the acid-added second slurry to be 1.0-2.0, reacting at constant temperature for 0.5-20 h, and collecting a second solid product.

Optionally, in the step a, the phosphorus-containing molecular sieve is a phosphorus-containing Y-type molecular sieve, the unit cell constant of the phosphorus-containing Y-type molecular sieve is 2.425-2.47 nm, and the specific surface area is 250-750 m²The pore volume is 0.2 to 0.95 mL/g.

Optionally, in the step b, the ratio of the weight of water in the first slurry to the dry weight of the phosphorus-containing molecular sieve raw material is (14-5): 1.

optionally, in step c, the ratio of the weight of water in the second slurry to the dry weight of the phosphorus-containing molecular sieve raw material is (0.5-20): 1.

optionally, in step c, the second acid solution is added in a manner that: based on 1L of the second slurry, taking H as reference⁺The second acid solution is added to the second slurry at a rate of 0.05 to 10 mol/h.

Optionally, in the step b, the acid concentration of the first acid solution is 0.01-15.0 mol/L, and the acid in the first acid solution is at least one selected from phosphoric acid, sulfuric acid, nitric acid, hydrochloric acid, acetic acid, citric acid, tartaric acid, formic acid and acetic acid; and/or the presence of a gas in the gas,

in the step c, the acid concentration of the second acid solution is 0.01-15.0 mol/L, and the acid in the second acid solution is at least one selected from phosphoric acid, sulfuric acid, nitric acid, hydrochloric acid, acetic acid, citric acid, tartaric acid, formic acid and acetic acid.

Optionally, the method further comprises: collecting the second product, then washing with water, and drying to obtain a phosphorus-containing silicon-aluminum molecular sieve; and/or, the drying conditions are as follows: the temperature is 50-350 ℃, and preferably 70-200 ℃; the time is 1-24 h, preferably 2-6 h.

A third aspect of the disclosure: there is provided a use of a phosphorus-containing, high silicon molecular sieve according to the first aspect of the disclosure in a hydrocracking reaction of a hydrocarbon feedstock.

Optionally, the hydrocarbon feedstock is a straight run gas oil, a vacuum gas oil, a demetallized oil, an atmospheric residue, a deasphalted vacuum residue, a coker distillate, a catalytically cracked distillate, a shale oil, a tar sand oil, or a coal liquefaction oil, or a combination of two or three thereof; and/or the presence of a gas in the gas,

the conditions of the hydrocracking reaction are as follows: the reaction temperature is 200-650 ℃, preferably 300-510 ℃; the reaction pressure is 3-24 MPa, preferably 4-15 MPa; the liquid hourly space velocity is 0.1-50 h^-1Preferably 0.2 to 30 hours^-1(ii) a The volume ratio of the hydrogen to the oil is 100-5000.

By adopting the technical scheme, the phosphorus-containing molecular sieve is adopted to carry out special hydrothermal treatment and two-step acid pickling treatment, so that the phosphorus-containing high-silicon molecular sieve with novel structural characteristics is prepared. Compared with the conventional amorphous silica-alumina material, the phosphorus-containing high-silica molecular sieve disclosed by the invention has better nitrogen stability, and shows higher hydrocracking activity when being used for preparing a hydrocracking catalyst.

Additional features and advantages of the disclosure will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure without limiting the disclosure. In the drawings:

FIG. 1 is an XRD spectrum of the molecular sieves prepared in preparative examples 1-2 and preparative comparative examples 1-3.

Detailed Description

The following detailed description of specific embodiments of the present disclosure is provided in connection with the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present disclosure, are given by way of illustration and explanation only, not limitation.

The first aspect of the disclosure: provides a phosphorus-containing high-silicon molecular sieve, the pore volume of the molecular sieve can be 0.20-0.50 mL/g, and the specific surface area can be 260-600 m²(ii) in terms of/g. The molecular sieve may have a silicon content of 90 to 99.8 wt%, an aluminum content of 0.1 to 9.0 wt%, and a phosphorus content of 0.01 to 2.5 wt%, based on the oxide and on the dry weight of the molecular sieve. In addition, the molecular sieve may also contain a small amount of sodium, and the sodium content of the molecular sieve may be 0.01 to 1.0 wt% calculated as oxides and based on the dry weight of the molecular sieve.

According to the present disclosure, the molecular sieve has different structural characteristics than conventional silica-alumina materials. Specifically, in an XRD spectrogram of the molecular sieve, the diffraction angle position of a first intensity peak is 5.9-6.9 degrees, and preferably 6.1-6.8 degrees; the diffraction angle position of the second strong peak is 10.0-11.0 degrees, preferably 10.2-10.7 degrees; the diffraction angle of the third intensity peak is 15.6 to 16.7 degrees, preferably 15.8 to 16.5 degrees. It is well known to those skilled in the art that in the material structure analysis by X-ray diffraction (XRD), the D value (interplanar distance) can be generally calculated by wavelength and diffraction angle, and the phase is primarily identified based on the features of the strongest three diffraction peaks, i.e., the first, second and third intensity peaks in the present disclosure. The concept of the three strong peaks can also be found in the literature, "Yi Yuan Gen Ming Dynasty" research method of heterogeneous catalysts [ M ]. Beijing: chemical industry Press, 1988.P140-170 ". Wherein, the diffraction angle position refers to the 2 theta angle value of the highest value of diffraction peak in the XRD spectrogram.

Further, in the XRD spectrogram of the molecular sieve, I₁/I_{23.5～24.5°}Can be 3.0 to 11.0, I₂/I_{23.5～24.5°}Can be 2.9 to 7.0, I₃/I_{23.5～24.5°}Can be 1.0 to 4.0, wherein I₁Is the peak height of the first strong peak, I₂Is the peak height of the second strong peak, I₃Is the peak height of the third strong peak, I_{23.5～24.5°}The peak height of the diffraction angle peak with the diffraction angle position of 23.5-24.5 degrees.

Further, in the XRD spectrogram of the molecular sieve, the diffraction angle position of a fourth intensity peak can be 20.4-21.6 degrees, preferably 20.8-21.4 degrees, and the diffraction angle position of a fifth intensity peak can be 11.8-12.8 degrees, preferably 12.1-12.6 degrees. Further, I₄/I_{23.5～24.5°}Can be 1.0-4.0, I₅/I_{23.5～24.5°}Can be 1.0 to 2.0, wherein I₄Is the peak height of the fourth strong peak, I₅Is the peak height of the fifth strong peak, I_{23.5～24.5°}The peak height of the diffraction angle peak with the diffraction angle position of 23.5-24.5 degrees. The concept of the fourth strong peak and the fifth strong peak can be understood according to the description of the three strong peaks, and will not be described herein again.

In a second aspect of the present disclosure: there is provided a process for preparing a phosphorus containing silicoaluminophosphate molecular sieve according to the first aspect of the present disclosure, the process comprising the steps of:

The phosphorus-containing molecular sieve is subjected to special hydrothermal treatment and two-step acid pickling treatment to prepare the phosphorus-containing high-silicon molecular sieve with novel structural characteristics.

According to the present disclosure, in step a, the phosphorus-containing molecular sieve raw material refers to a phosphorus-containing molecular sieve. The method adopts the phosphorus-containing molecular sieve as a raw material, and phosphorus aluminum species outside the molecular sieve framework can improve the framework stability of the molecular sieve, so that the performance of the molecular sieve is further improved. The structure of the phosphorus-containing molecular sieve raw material can be an octahedral zeolite molecular sieve structure, preferably a phosphorus-containing Y-type molecular sieve, the unit cell constant of the phosphorus-containing molecular sieve raw material can be 2.425-2.47 nm, and the specific surface area of the phosphorus-containing molecular sieve raw material can be 250-750 m²The pore volume may be 0.2 to 0.95 mL/g. Further, the specific selection of the Y-type molecular sieve may be widely varied as long as the phosphorus-containing molecular sieve raw material satisfies the above conditions, and for example, the Y-type molecular sieve may be selected from NaY, HNaY (hydrogen Y-type molecular sieve), REY (rare earth Y-type molecular sieve), USY (ultra stable Y-type molecular sieve), and the like. The cation position of the phosphorus-containing Y-type molecular sieve can be replaced by sodium ions, ammonium ions and hydrogenOne or more of the ions; alternatively, the sodium, ammonium, and hydrogen ions may be replaced by other ions, either before or after the molecular sieve is introduced with phosphorus, by conventional ion exchange. The phosphorus-containing molecular sieve raw material can be a commercial product, and can also be prepared by any prior art, for example, a method for preparing USY disclosed in a patent ZL00123139.1, or a method for preparing PUSY disclosed in a patent ZL200410071122.6 and the like can be adopted, and the details of the disclosure are not repeated.

The meaning of said water addition beating in step b and step c is well known to the person skilled in the art in light of the present disclosure. In the step b, the ratio of the weight of water in the first slurry obtained after pulping to the dry basis weight of the phosphorus-containing molecular sieve raw material can be (14-5): 1. in the step c, the ratio of the weight of water in the second slurry to the dry weight of the phosphorus-containing molecular sieve raw material may be (0.5-20): 1.

according to the present disclosure, in the step b, the first slurry is preferably heated to 50 to 85 ℃, and then the temperature is maintained and the first acid solution is continuously added to the first slurry until the pH value of the first slurry after the acid addition reaches the required value. The amount of the first acid solution added can vary widely according to the nature of the phosphorus-containing molecular sieve feedstock and the hydrothermal treatment conditions of step a, and it will be understood by those skilled in the art that the amount of the first acid solution added is reasonable as long as the pH of the acidified first slurry meets the above suitable range. The rate of addition of the first acid solution is not particularly limited and may vary over a wide range.

According to the disclosure, in the step b, the operation of adding the first acid solution may be performed multiple times (e.g., 1 to 5 times), and after each time of adding the acid, the reaction may be performed at a constant temperature for a period of time, and then the next time of adding the acid is continued until the pH value of the first slurry after adding the acid reaches a required range. The acid concentration of the first acid solution can be 0.1-15.0 mol/L, and the pH value can be 0.01-3. The acid in the first acid solution may be a conventional inorganic acid and/or organic or acid, and may be, for example, at least one selected from phosphoric acid, sulfuric acid, nitric acid, hydrochloric acid, acetic acid, citric acid, tartaric acid, formic acid, and acetic acid.

According to the present disclosure, in step c, the second slurry is preferably heated to 50-85 ℃, and then the temperature is maintained and the second acid solution is continuously added to the second slurry until the pH of the acid-added second slurry reaches the desired value. The second acid solution may be added in a manner that: based on 1L of the second slurry, taking H as reference⁺Adding the second acid solution into the second slurry at a speed of 0.05-10 mol/h. Thus, the acid adding speed is slower in the step c, so that the dealumination process is more moderate, and the performance of the molecular sieve is favorably improved.

According to the disclosure, in the step c, the operation of adding the second acid solution may be performed multiple times (e.g., 1 to 5 times), and after each time of adding the acid, the second acid solution may be reacted at a constant temperature for a period of time and then the next time of adding the acid is continued until the pH value of the second slurry after adding the acid reaches a desired range. The acid concentration of the second acid solution can be 0.1-15.0 mol/L, and the pH value can be 0.01-3. The acid in the second acid solution may be a conventional inorganic acid and/or organic or acid, and may be, for example, at least one selected from phosphoric acid, sulfuric acid, nitric acid, hydrochloric acid, acetic acid, citric acid, tartaric acid, formic acid, and acetic acid. The second acid solution may be the same as or different from the first acid solution in terms of kind and concentration, and is preferably the same acid solution.

According to the present disclosure, the method may further comprise: and collecting the second product, and then washing and drying to obtain the phosphorus-containing silicon-aluminum molecular sieve. The washing and drying are conventional steps for preparing the molecular sieve, and the disclosure is not particularly limited. For example, the drying may be performed by using an oven, a mesh belt, a converter, or the like, and the drying conditions may be: the temperature is 50-350 ℃, and preferably 70-200 ℃; the time is 1-24 h, preferably 2-6 h.

Compared with the conventional amorphous silica-alumina material, the phosphorus-containing silica-alumina molecular sieve disclosed by the invention has better nitrogen stability and shows higher hydrocracking activity when being used for preparing a hydrocracking catalyst.

The phosphorus-containing high-silicon molecular sieve provided by the disclosure can be used as various acid catalytic catalysts for catalytic cracking, hydroisomerization, alkylation, hydrocracking and other reactions, and is particularly suitable for hydrocracking hydrocarbon raw materials to produce hydrocarbon fractions with lower boiling points and lower molecular weights. Accordingly, the third aspect of the present disclosure: there is provided a use of a phosphorus-containing, high silicon molecular sieve according to the first aspect of the disclosure in a hydrocracking reaction of a hydrocarbon feedstock.

The hydrocarbon feedstock may be various heavy mineral oils or synthetic oils or their mixed distillates, such as straight run gas oil (straight run gas oil), vacuum gas oil (vacuum gas oil), demetalized oils (demetalized oils), atmospheric residues (atmospheric residues), deasphalted vacuum residues (deasphalted vacuum residues), coker distillates (coker distillates), catalytic cracker distillates (cat cracker distillates), shale oils (shell oils), tar sand oils (tar sand oils), coal liquefied oils (coal liquids), etc. In particular, the catalyst provided by the disclosure is particularly suitable for hydrocracking heavy and poor distillate oil to produce a hydrocracking process of middle distillate oil with the distillation range of 149-371 ℃, especially 180-370 ℃.

The hydrocracking process can be one or more of conventional hydrocracking processes such as a fixed bed, an ebullated bed, a slurry bed, a suspended bed and the like.

The catalyst provided by the present disclosure can be used under conventional hydrocracking process conditions when used for distillate oil hydrocracking, for example, the hydrocracking reaction conditions are as follows: the reaction temperature is 200-650 ℃, the preferable temperature is 300-510 ℃, the reaction pressure is 3-24 MPa, the preferable pressure is 4-15 MPa, and the liquid hourly space velocity is 0.1-50 h^-1Preferably 0.2 to 30 hours^-1The volume ratio of hydrogen to oil is 100-5000.

The present disclosure is further illustrated by the following examples, but is not limited thereto.

The pore volume and the specific surface area of the molecular sieve are measured by a static low-temperature adsorption capacity method (by adopting a national standard GB/T5816-1995 method) by adopting an ASAP 2400 model automatic adsorption instrument of American micromeritics instruments, and the specific method comprises the following steps: vacuumizing and degassing at 250 deg.C and 1.33Pa for 4 hr, contacting with nitrogen as adsorbate at-196 deg.C, and statically reaching adsorption balance; and calculating the nitrogen adsorption amount of the adsorbent according to the difference between the nitrogen gas inflow and the nitrogen gas remaining in the gas phase after adsorption, calculating the pore size distribution by using a BJH (British Ribose) formula, and calculating the specific surface area and the pore volume by using a BET (BET) formula.

The crystal structure of the molecular sieve is determined by an X-ray diffractometer D5005 of Siemens Germany, and the method is in an industry standard SH/T0339-92. The experimental conditions are as follows: cu target, Ka radiation, solid detector, tube voltage 40kV, tube current 40mA, step scanning, step width of 0.02 degrees, prefabrication time of 2s and scanning range of 5-70 degrees. The diffraction angle position refers to the 2 theta angle value of the highest peak value of the diffraction peak.

The silicon content, aluminum content, phosphorus content and sodium content of the molecular sieve are measured by a 3271E type X-ray fluorescence spectrometer of Nippon science and Motor industry Co., Ltd, and the measuring method comprises the following steps: tabletting and forming a powder sample, carrying out rhodium target, detecting the spectral line intensity of each element by a scintillation counter and a proportional counter under the laser voltage of 50kV and the laser current of 50mA, and carrying out quantitative and semi-quantitative analysis on the element content by an external standard method.

Preparative examples 1-2 are provided to illustrate methods of preparing phosphorus-containing high silicon molecular sieves provided by the present disclosure.

Preparation of example 1

Taking RY molecular sieve (produced by China petrochemical catalyst Chang Ling division, cell constant is 2.456nm, specific surface area is 672 m)²Per g, pore volume of 0.357mL/g, Na₂O content 1.44 wt.%, P₂O₅Content 1.37 wt%) was put into a hydrothermal kettle, 100% steam was introduced, and the molecular sieve material after hydrothermal treatment was taken out after hydrothermal treatment at 560 ℃ and 0.8MPa for 3 hours.

Taking 50g (dry basis) of the obtained molecular sieve material subjected to the hydrothermal treatment, adding 500mL of deionized water, stirring and pulping to obtain first slurry, heating the first slurry to 80 ℃, adding 2.0mol/L sulfuric acid solution, stopping adding acid when the pH value of the first slurry after acid addition is detected to be 2.8, then carrying out constant-temperature reaction for 4h, and filtering to obtain 40g of a first solid product.

Adding 400mL of deionized water into the first solid product, stirring and pulping to obtainSecond slurry, which was warmed to 80 ℃. Based on 1L of the second slurry, H⁺Adding 2mol/L sulfuric acid solution into the second slurry at a speed of 5mol/h, stopping adding acid when the pH value of the second slurry after acid addition is detected to be 1.4, then reacting at a constant temperature for 3h, filtering, collecting a second solid product, and drying at 180 ℃ for 3h to obtain the phosphorus-containing silicon-aluminum molecular sieve Y-1, wherein an XRD spectrogram of the phosphorus-containing silicon-aluminum molecular sieve Y-1 is shown in figure 1, and can be seen, wherein the diffraction angle position of a first strong peak is 6.1-6.8 degrees, the diffraction angle position of a second strong peak is 10.2-10.7 degrees, the diffraction angle position of a third strong peak is 15.8-16.5 degrees, the diffraction angle position of a fourth strong peak is 20.8-21.4 degrees, and the diffraction angle position of a fifth strong peak is 12.1-12.6 degrees. Other properties are shown in table 1.

Preparation of example 2

A high silicon molecular sieve was prepared as in preparative example 1, except that the second acid solution was added at a rate of 15 mol/h. The prepared molecular sieve Y-2 has an XRD spectrogram shown in figure 1, and can be seen, wherein the diffraction angle position of a first intensity peak is 6.1-6.8 degrees, the diffraction angle position of a second intensity peak is 10.2-10.7 degrees, the diffraction angle position of a third intensity peak is 15.8-16.5 degrees, the diffraction angle position of a fourth intensity peak is 20.8-21.4 degrees, and the diffraction angle position of a fifth intensity peak is 12.1-12.6 degrees. Other properties are shown in table 1.

Comparative examples 1-3 are prepared to illustrate different methods of preparing phosphorus-containing molecular sieves than the present disclosure.

Preparation of comparative example 1

The molecular sieve of the comparative preparation example is a PSRY molecular sieve, the preparation method refers to CN1088407C example 1, the PSRY molecular sieve is named as DY-1, and an XRD spectrogram is shown in figure 1, so that the diffraction angle position of a first intensity peak is 6.0-6.5 degrees, the diffraction angle position of a second intensity peak is 15.7-16.2 degrees, the diffraction angle position of a third intensity peak is 23.5-24.0 degrees, the diffraction angle position of a fourth intensity peak is 20.4-20.7 degrees, the diffraction angle position of a fifth intensity peak is 10.0-10.5 degrees, and the PSRY molecular sieve is different from the phosphorus-containing silicon-aluminum molecular sieve of the preparation example 1. Other properties are shown in table 1.

Preparation of comparative example 2

Taking HY molecular sieve without phosphorus (produced by Zhongshiedification catalyst Chang Ling division)HY, unit cell constant 2.465nm, specific surface area 580m²Per g, pore volume of 0.33mL/g, Na₂0.3 wt.% of O, Al₂O₃Content of 22 wt%) was put into a hydrothermal kettle, 100% steam was introduced, and the molecular sieve material after hydrothermal treatment was taken out after hydrothermal treatment at 500 ℃ and 2.0MPa for 1 hour.

And taking 80g (dry basis) of the obtained molecular sieve material subjected to the hydrothermal treatment, adding 500mL of deionized water, stirring and pulping to obtain first slurry, heating the first slurry to 80 ℃, adding 1.0mol/L sulfuric acid solution, stopping adding acid when the pH value of the first slurry after acid addition is detected to be 3.0, then reacting at constant temperature for 4 hours, and filtering to obtain 65g of first solid product.

And adding 600mL of deionized water into the first solid product, stirring and pulping to obtain second slurry, and heating the second slurry to 80 ℃. Based on 1L of the second slurry, H⁺Adding 1.0mol/L phosphoric acid solution into the second slurry at a speed of 2mol/h, stopping adding acid when the pH value of the second slurry after adding acid is detected, then reacting for 3h at a constant temperature, filtering, collecting a second solid product, and drying for 3h at 180 ℃ to obtain a phosphorus-containing silicon-aluminum molecular sieve DY-2, wherein an XRD spectrogram of the phosphorus-containing silicon-aluminum molecular sieve DY-2 is shown in figure 1, and can be seen, wherein the diffraction angle position of a first strong peak is 5.5-6.2 degrees, the diffraction angle position of a second strong peak is 15.7-16.2 degrees, the diffraction angle position of a third strong peak is 10.0-10.5 degrees, the diffraction angle position of a fourth strong peak is 11.8-12.2 degrees, and the diffraction angle position of a fifth strong peak is 20.3-20.7 degrees. Other properties are shown in table 1.

Preparation of comparative example 3

500g of RY molecular sieve (same as example 1) is taken and placed into a hydrothermal kettle, 100 percent of steam is introduced, and after hydrothermal treatment is carried out for 3 hours at 560 ℃ and 0.8MPa, the molecular sieve material after the hydrothermal treatment is taken out.

Taking 60g (dry basis) of the obtained molecular sieve material after the hydrothermal treatment, adding 500mL of deionized water, stirring and pulping to obtain first slurry, heating the first slurry to 90 ℃, adding 2.0mol/L sulfuric acid solution, stopping adding acid when the pH value of the first slurry after acid addition is detected to be 2.5, then reacting at a constant temperature for 4 hours, filtering to obtain 60g of a first solid product, and drying at 180 ℃ for 3 hours to obtain a phosphorus-containing silicon-aluminum molecular sieve DY-3, wherein an XRD (X-ray diffraction) spectrum of the molecular sieve DY-3 is shown in figure 1, as can be seen, the diffraction angle position of a first strong peak is 15.7-16.0 degrees, the diffraction angle position of a second strong peak is 6.0-6.5 degrees, the diffraction angle position of a third strong peak is 23.7-24.3 degrees, the diffraction angle position of a fourth strong peak is 11.5-12.0 degrees, and the diffraction angle position of a fifth strong peak is 10.0-10.5 degrees, which are different from the phosphorus-containing silicon-aluminum molecular. Other properties are shown in table 1.

TABLE 1

Examples 1-2 are intended to illustrate catalysts prepared using the molecular sieves provided in this disclosure. Comparative examples 1-3 are presented to illustrate catalysts prepared using different molecular sieves than those of the present disclosure.

Example 1

80g Y-1 dry-based molecular sieve and 20g of pseudo-boehmite (product name PB90, dry basis 70 wt%) are mixed, extruded into a trilobal strip with the circumscribed circle diameter of 1.6 mm, dried at 120 ℃ for 3h and roasted at 600 ℃ for 3h to obtain the carrier CS-1. After cooling to room temperature, 100g of the CS-1 carrier was immersed in 70mL of an aqueous solution containing 34.65g of ammonium metatungstate (82 wt% tungsten oxide, product of the mitsubao co company cemented carbide works, beijing new photochemical reagent works, 27.85 wt% nickel oxide) and 24.37g of nickel nitrate, dried at 120 ℃ for 3 hours, and calcined at 480 ℃ for 4 hours, thereby obtaining the catalyst prepared in this example.

Example 2

A catalyst was prepared as in example 1, except that Y-2 was used as the molecular sieve.

Comparative examples 1 to 3

A catalyst was prepared as in example 1, except that the molecular sieves used were DY-1, DY-2 and DY-3, respectively.

Test examples

This test example was used to test the catalytic activity of the catalysts of examples 1-2 and comparative examples 1-3 for hydrocracking reactions.

Containing 5.61% of tetrahydronaphthalene and 0.29% of pyridineNormal octane is used as a raw material, the hydrocracking activity of the catalyst is evaluated on a small fixed bed hydrocracking device, the catalyst loading is 0.2 ml, the reaction temperature is 320 ℃, the reaction pressure is 4.0MPa, the hydrogen-oil volume ratio is 3600, and the liquid hourly space velocity is 30h^-1After the reaction feed had stabilized for 4h, the catalyst activity was represented as the percentage of n-decane converted in the product composition, and the results of the evaluation are shown in Table 2.

TABLE 2

Catalyst and process for preparing same	Conversion (%)
		Example 1	78.0
Example 2	71.2
		Comparative example 1	54.3
Comparative example 2	63.2
		Comparative example 3	58.3

As can be seen from table 2, under the same comparative conditions, the catalyst containing the phosphorus-containing aluminosilicate molecular sieve provided by the present disclosure has a catalytic activity improved by about 7% or more under high nitrogen conditions, compared to the molecular sieve prepared by the prior art method.

The preferred embodiments of the present disclosure are described in detail with reference to the accompanying drawings, however, the present disclosure is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present disclosure within the technical idea of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.

It should be noted that, in the foregoing embodiments, various features described in the above embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various combinations that are possible in the present disclosure are not described again.

In addition, any combination of various embodiments of the present disclosure may be made, and the same should be considered as the disclosure of the present disclosure, as long as it does not depart from the spirit of the present disclosure.

Claims

1. The phosphorus-containing high-silicon molecular sieve is characterized in that the pore volume of the molecular sieve is 0.20-0.50 mL/g, and the specific surface area is 260-600 m²The content of silicon, aluminum and phosphorus of the molecular sieve is 90-99.8 wt%, 0.1-9.0 wt% and 0.01-2.5 wt%, respectively, calculated by oxide and based on the dry weight of the molecular sieve;

2. The molecular sieve according to claim 1, wherein the XRD spectrum of the molecular sieve has diffraction angle positions of a first intensity peak at 6.1-6.8 °, a second intensity peak at 10.2-10.7 °, and a third intensity peak at 15.8-16.5 °.

3. The molecular sieve of claim 1 or 2, wherein the molecular sieve has an XRD spectrum with I₁/I_{23.5～24.5°}Is 3.0 to 11.0, I₂/I_{23.5～24.5°}Is 2.9 to 7.0, I₃/I_{23.5～24.5°}1.0 to 4.0, wherein I₁Is the peak height of the first strong peak, I₂Is the peak height of the second strong peak, I₃Is the peak height of the third strong peak, I_{23.5～24.5°}The peak height of the diffraction angle peak with the diffraction angle position of 23.5-24.5 degrees.

4. The molecular sieve according to claim 1 or 2, wherein the XRD spectrum of the molecular sieve has diffraction angle positions of a fourth intensity peak of 20.4-21.6 ° and diffraction angle positions of a fifth intensity peak of 11.8-12.8 °.

5. The molecular sieve according to claim 4, wherein the XRD spectrum of the molecular sieve has diffraction angle positions of a fourth intensity peak in the range of 20.8-21.4 ° and diffraction angle positions of a fifth intensity peak in the range of 12.1-12.6 °; and/or the presence of a gas in the gas,

6. A method for preparing the phosphorus-containing high silicon molecular sieve of any one of claims 1 to 5, comprising the following steps:

7. The method of claim 6, wherein in the step a, the phosphorus-containing molecular sieve raw material is a phosphorus-containing Y-type molecular sieve, the unit cell constant of the phosphorus-containing Y-type molecular sieve is 2.425-2.47 nm, and the specific surface area is 250-750 m²The pore volume is 0.2 to 0.95 mL/g.

8. The method of claim 6, wherein in step b, the ratio of the weight of water in the first slurry to the dry weight of the phosphorus-containing molecular sieve feedstock is (14-5): 1.

9. the method of claim 6, wherein in step c, the ratio of the weight of water in the second slurry to the dry weight of the phosphorus-containing molecular sieve feedstock is (0.5-20): 1.

10. the process of claim 6, wherein in step c, the second acid solution is added by: based on 1L of the second slurry, taking H as reference⁺The second acid solution is added to the second slurry at a rate of 0.05 to 10 mol/h.

11. The method according to claim 6, wherein in the step b, the acid concentration of the first acid solution is 0.01-15.0 mol/L, and the acid in the first acid solution is at least one selected from phosphoric acid, sulfuric acid, nitric acid, hydrochloric acid, acetic acid, citric acid, tartaric acid, formic acid and acetic acid; and/or the presence of a gas in the gas,

12. The method of claim 6, wherein the method further comprises: collecting the second product, then washing with water, and drying to obtain a phosphorus-containing silicon-aluminum molecular sieve; and/or, the drying conditions are as follows: the temperature is 50-350 ℃, and preferably 70-200 ℃; the time is 1-24 h, preferably 2-6 h.

13. Use of the phosphorus-containing high-silicon molecular sieve according to any one of claims 1 to 5 in a hydrocracking reaction of a hydrocarbon feedstock.

14. The use according to claim 13, wherein the hydrocarbon feedstock is a straight run gas oil, a vacuum gas oil, a demetallized oil, an atmospheric residue, a deasphalted vacuum residue, a coker distillate, a catalytically cracked distillate, a shale oil, a tar sand oil, or a coal liquefaction oil, or a combination of two or three thereof; and/or the presence of a gas in the gas,